Design



I 1,319,076. Patent ed Oct. 21,1919,

C. HERMANN;

DESIGN PLATEOR CYLINDER FOR LITHOGRAPHIC PRINTING MACHINES. v

- APPLICATION FILED DEc.21. I9I6- k/nwmzi/x awg/ CASPAR HERMANN, F BALTIMORE, MARYLAND.

DESIGN PLATE OR CYLINDER FOR LITHOG-RAPHIG-PRINTING IVIAGHINES.

Application filed December 27, 1916.

To all whom it may concern: 1

Be it known that I, OAsrAR HERMANN, a

. citizen of the United States of America, re-

siding at Baltimore, State of Maryland, have invented certain new and useful Improvements in Design Plates or Cylinders for Lithographic-Printing Machines, of which the following is a specification.

My invention relates to the art of print ing by means of lithographic printing machines or web presses having design-plates or design-cylinders in which the design to be printed, that is, the faces which receive the printing ink for deposit onto the paper or other material to be printed, consists of.

taglio, and consists in making or composing the printing surface, of the plate or cylinder, partly of a metal or alloy behaving refractory with respect to lithographic inks, such as copper, and partly of a metal or alloy suitable for receiving lithographic inks such as zinc or aluminum. The part of the surface made of a refractory metal is that which is smooth and inactive and the part of the surface made of zinc or any other lithographic metal or alloy is the design that is the carved or etched active" part of the printing plate or cylinder.

In printing machines of the kind hitherto known the printing surfaces of the design-plates or cylinders consist of a single metal such as zinc which is soon worn out so that only a limited number of copies can be taken therefrom and large editions of printed matter or the like can therefore not be made with 'a single design-plate or cylinder.

My invention is shown in the accompanying drawing wherein:

Specification of Letters Patent.

PatentedOct. 21, 1919.

Serial No. 139,147.

Figure 1 is a sectional view of part of a design-plate embodying the invention, on an enlarged scale.

Fig, 2 is a similar sectional view of a modification of the plate.

In carrying out my invention I use a design or printing plate or cylinder made of either a refractory alloy or metal (copper or the like) or of a lithographic alloy or metal (zinc, aluminum or the like) havin a thin coat of refractory metal or alloy. 11 Fig. 1 the printing plate consists of copper a or the like, and in Fig. 2 the plate consists of zinc b or the like. In either case I produce the intaglio design. 0 on the printing face of the plate or cylinder by means of etching or in any other known manner. In case of Fig. 1 where the plate consists of copper (or at least has a solid top layer of copper) I galvanize the etched design surface so that the design is'covered by a coat of zinc 7) suitable for receiving a lithographic ink. In galvanizing the plate the smooth inactive parts 03 of the surface also receive a zinc coat which however is removed again by grinding or in any other suitable man ner, so that only the etched parts 0 (that is the design) are zinc coated and thereby adapted to receive lithographic ink whereas the smooth inactive parts 03 are of refractory metal.

In case of Fig. 2 the plate consists of zinc (a zinc alloy or the like) with a light coat of copper a thereon. This copper coat is destroyed by the etching liquid at the places representing the design a so that the latter has a zinc surface or bottom adapted to receive lithographic ink.

hat I claim is:

A design plate or cylinder for lithographic printing-machines comprising smooth inactive parts made of copper, and intaglio design re-producing parts made of zinc.

In testimony whereof I have afiixed my signature in presence of two witnesses.

GASPLAR HERMANN.

Witnesses:

ROBERT TRUMAN Rom, CHRISTIAN KNARR. 

